The use of reverse osmosis water for the production of parenterals in the hospital pharmacy

Abstract

Only theUnited States Pharmacopeia has included reverse osmosis as an approved process for producing ‘Water for Injection’ to date. In the author's hospital pharmacy water for the production of large volume parenterals is being produced by means of an installation containing the Du-Pont Permasep ® hollow fiber permeator. Technical details and chemical background of this system are discussed. The permeator is fed by mixed bed deionised water of very low solids content. The main advantages of such a system, which does produce water conforming to pharmacopoeial specifications, are the small initial investment and running costs as compared with a distillation unit; the fact that no heat energy is required and that the production rate of pyrogen free water is as high as 300 l/h and upwards, thus obviating the need for storage.

Disadvantages are the need for a variety of monitoring arrangements to control correct membrane function, especially membrane integrity and the possible leakage past gaskets; the necessity of regular sanitisation with formaldehyde, which is not without its own inherent difficulties; and the fact that an absolutely sterile product water cannot be consistently guaranteed. Some of these aspects are also discussed with respect to the recent CGMP/LVP proposals of FDA.